Portable devices used by the general public need to meet regulatory specific absorption rate (SAR) compliance requirements (e.g., refer to Federal Communications Commission (FCC) Part 15—Radio Frequency (RF) exposure requirements). The need to limit a user's exposure to RF energy from a portable device (in particular, from the device's RF transmitter antenna) under the regulatory thresholds may necessitate a need in certain use cases to limit the transmitter power at a level (PSARMAX), which is below the maximum transmitter power (PMAX). In such cases, during which a portable device may be closer to human body than in other use case scenarios, the RF exposure to the user from the device may exceed mandatory SAR exposure limits if the transmitter of the device is allowed to operate at its maximum transmitter power.
On the other hand, unnecessarily cutting back the transmitter power of the device in situations where the device is not close to human body, or the device is being operated in a way that does not cause SAR exposure above compliance limits, would result in reduced wireless link performance and network range (e.g., in cellular networks, wireless local area network (WLAN) networks, etc.). As such, there is a need for an improved design for determining the relationship of RF devices to proximate humans to determine maximum permissible transmitter power within SAR requirements.